1. Field of the Invention
The present invention relates to a gas turbine installation in which turbine cooling air is cooled with latent heat absorbed in evaporation of sprayed water droplets.
2. Description of the Related Art
Generally, in a gas turbine installation employing a part of compressed air generated from a compressor as turbine cooling air, an improvement in power generation efficiency and an increase in output of a gas turbine system can be achieved by increasing a cooling capability of cooling air and reducing the amount of compressed air required for the cooling. To that end, a technique for reducing the flow rate of compressed air required for cooling blades is practiced which employs a heat exchanger disposed midway an extraction pipe extending from the compressor, for example, to cool the turbine cooling air.
Also, a paper 83-GT-66 of ASME (American Society of Mechanical Engineers), i.e., Non-Patent Reference 1; ASME, 83-GT-66, discusses feasibility of a technique for spraying water droplets into the turbine cooling air and lowering the temperature of the turbine cooling air with latent heat absorbed in evaporation of the sprayed water droplets. This paper also discloses that the combustion temperature in a combustor is temporarily raised to increase the output of a gas turbine, and water is sprayed into the turbine cooling air for the purposes of increasing the blade cooling capability and maintaining the reliability of blades.